Volume 11, Number 1,March 2018 ISSN 1995-6673 JJBS Pages 81 - 85 Jordan Journal of Biological Sciences Morphometric Relationships of the Tank goby Glossogobius giuris (Hamilton, 1822) in the Gorai River using Multi-linear Dimensions Md. Abul Kalam Azad, Md. Yeamin Hossain*, Dalia Khatun, Most. Farida Parvin, Fairuz Nawer, Obaidur Rahman and Md. Alomgir Hossen Department of Fisheries, Faculty of Agriculture, University of Rajshahi, Bangladesh. Received July 24, 2017; Revised September 14, 2017; Accepted September 26, 2017 Abstract The present study illustrates the first complete and inclusive information of morphometric relationships, including Length- Weight Relationships (LWRs) and Length-Length Relationships (LLRs), using a total of 13 linear dimensions of Glossogobius giuris (Hamilton, 1822) in the Gorai River, southwestern (SW) Bangladesh. Also meristic characters, including various fin-rays of the tank goby, have been studied. In total, 229 specimens of G. giuris were collected occasionally from the Gorai River during March 2016 to February 2017 by a variety of local fishing gears (e.g., cast, gill, and square lift net). Fin rays and scales (including lateral line scale) were counted by a magnifying glass. Different morphometric lengths were measured to 0.01 cm, and whole Body Weight (BW) was estimated ± 0.01 g for each individual. The fin formula of G. giuris is: dorsal, D1. VI; D2. 8–11 (II–III/8–11); pectoral, P1. 17–22 (II–VI/14–19); pelvic, P2. 10–13 (II–III/8–10); anal, A. 7–12 (II–IV/5–8); and caudal, C. 16–21 (IV–VIII/12–13), correspondingly. In the present study, Total Length (TL) varied from 4.3 to 26.9 cm and BW ranged from 0.67 to 146.55g. All LWRs were highly significant (p < 0.0001) with r2 values ≥ 0.975. Based on r2 value, LWR by BW vs. TL, BW vs. SL and BW vs. PoAnL were good fitted models among 13 equations. The present study would be very valuable for species recognition and stock assessment of tank goby in the Gorai River, SW Bangladesh and in adjoining ecosystems. Keywords: Tank goby; Fin rays; Glossogobius giuris; Meristic; Morphometric. 1999; Hossen et al., 2016). Moreover, in fisheries 1. Introduction research, appraising the well-being of individuals as well as evaluating the life history and the morphological traits The tank goby Glossogobius giuris (Hamilton, 1822), of populations of different locality greatly rely on belonging to the family Gobiidae, is a benthopelagic; morphometric characters (King, 2007; Hossain, 2010; amphidromous species occurring in sea-, brackish- and Hossain et al., 2013). fresh-waters. It is the only species of diverse genus To the best of our knowledge, a few studies, including Glossogobius, found in Bangladesh, locally known as Bele morphometric and meristic characters, Length-Weight (Rahman, 2005), Bhaila in India, Tank goby in Malaysia, Relationships (LWRs), food and feeding habits, Goby in Philippine (Freose and Pauly, 2016). G. giuris reproduction and breeding performance, have been inhabits streams, canals, ditches and ponds. This goby fish conducted on this species from other habitats (Hossain et is broadly distributed in coastal and estuarine as well as al., 2009; Mollah et al., 2012; Islam and Mollah, 2013; fresh waters alongside the coasts of East Africa, the Red Hossain, 2014; Islam et al., 2014; Kaur and Rawal, 2015; Sea and the Indian subcontinent to China (Freose and Qambrani et al., 2015; Hossain et al., 2016; Saha et al., Pauly, 2016). It is very rich in protein and micronutrients 2016); however, no sound studies on this issue, covering a and has high market value (Islam and Joadder, 2005; Islam large number of linear dimensions, have been conducted et al., 2014). This fish is one of the dominant species in the yet from the Gorai River. Therefore, the present study is Gorai River (SW Bangladesh); hence, it is an important designed to describe the morphometric and meristic capture species for small- and large- scale fishermen characteristics of G. giuris systematically using large (Costa et al., 1999; Hossain et al., 2009). number of specimens from small to larger sizes over a Studies on morphometric and meristic features can be study period of one year from the Gorai River (SW constructive tools for exact identification of any species Bangladesh). and its classification (Begenal and Tesch, 1978; Jayaram, * Corresponding author. e-mail: [email protected]. 82 © 2018 Jordan Journal of Biological Sciences. All rights reserved - Volume 11, Number 1 2. Materials and Methods regression analysis (Hossain et al., 2006). Best/ good model for both LWRs and LLRs was selected based on the In the present study, a total of 229 individuals of G. highest value of determination r2. Total number of fin rays giuris (Figure 1) were collected occasionally from the and scales from different body parts (including the lateral Gorai (distributary of Ganges River) River (Latitude: 23° line) were counted by using magnifying glass. Statistical 32' N; Longitude: 89° 31' E), SW Bangladesh during analyses were performed using Graph Pad Prism 6.5 March 2016 to February 2017 from artisanal fishers. The software. All statistical analyses were considered samples were caught using various types of traditional significant at 5% (p < 0.05). fishing gears, i.e., cast net (mesh size ranges: 1.5 - 2.5 cm), gill net (mesh size ranges: 1.5–2.0 cm), and square lift net (mesh size: ~2.0 cm). The fresh samples (dead fish) were instantly chilled in ice on site and preserved with 10% buffered formalin after arrival in the laboratory. Total Body Weight (BW) of each individual was taken using a digital electric balance with 0.01 g accuracy and different linear dimensions, i.e., lengths (Table 1 and Fig. 2) Figure 1. A photo of Glossogobius giuris which was collected were estimated to the nearest 0.01 cm using digital slide from the Gorai River, southwestern Bangladesh calipers. The LWR was estimated using the equation: W= a× Lb, where W is the body weight (BW, g) and L is the 13 different lengths in cm. The regression parameters a and b were calculated by linear regression analyses based on natural logarithms: ln (W) = ln(a) + b ln(L). Moreover, 95% Confidence Limit (CL) of a and b and the co-efficient of determination (r2) were estimated. Extremes outliers were removed from the regression analyses according to Froese (2006). A t-test was used to confirm whether b values obtained in the linear regressions were significantly Figure 2. Showing the morphometric measurements of Glossogobius giuris in the Gorai River, southwestern Bangladesh different from the isometric (b = 3) value (Sokal and Rohlf 1987). A total of 12 LLRs were estimated by linear Table 1. Morphometric measurements of the Glossogobius giuris (Hamilton, 1822) (n = 229) captured from the Gorai River, southwestern Bangladesh Min, minimum; Max, maximum; SD, standard deviation; CL, confidence limit for mean values; TL, total length; SL, standard length; BW, body weight; PrDL 1,1st Pre-dorsal length; PoDL 1,1st Post-dorsal length; PrDL 2, 2nd Pre-dorsal length; PoDL 2, 2nd Post-dorsal length; HL, Head length; OprL, Opercular length; PcL, Pectoral length; PvL, pelvic length; AnsL, anus length; PrAnL, pre-anal length; PoAnL, post- Measurements Min (cm) Max (cm) Mean ± SD 95% CL %TL TL (Total length) 4.3 26.9 12.803±5.893 12.036-13.571 SL (Standard length) 3.3 19.5 9.867±4.535 9.276-10.457 76.728 PrDL 1(1st Pre-dorsal length) 1.2 7.8 3.679±1.705 3.457-3.901 37.291 PoDL 1(1st Post-dorsal length) 1.5 10.1 4.810±2.226 4.520-5.099 37.401 PrDL 2(2nd Pre-dorsal length) 1.9 11.6 5.658±2.594 5.320-5.995 43.996 PoDL 2(2nd Post-dorsal length) 2.5 15.6 7.564±3.470 7.112-8.016 58.822 HL (Head length) 0.9 6.3 2.914±1.362 2.737-3.092 22.664 OprL (Opercular length) 0.8 6.2 2.781±1.372 2.602-2.959 21.625 PcL (Pectoral length) 0.9 6.3 2.964±1.410 2.781-3.148 23.051 PvL (Pelvic length) 1.1 6.4 3.110±1.449 2.922-3.299 24.188 AnsL(Anus length) 1.4 11.8 5.535±2.710 5.182-5.888 43.045 PrAnL(Pre-anal length) 1.9 12.3 6.000±2.766 5.640-6.360 46.658 BW (Body weight) 0.67* 146.55* 27.731±33.217 23.406-32.056 anal length; *, weight in g). © 2018 Jordan Journal of Biological Sciences. All rights reserved - Volume 11, Number 1 83 meristic measurements are presented in Table 1 and 2, 3. Results respectively. In the present study, TL was ranged from 4.3 to 26.9 cm (mean ± SD = 12.80±5.89) and the BW was The body of G. giuris is elongated and moderately varied from 0.67 to 146.55g (mean ± SD = compressed, mouth oblique with prominent lower jaw and 27.731±33.217). The standard length (76.73%) contains flattened head. The body color is brownish yellow with 5 the high percentage of TL (Table 1). to 6 dark and rounded spots on its sides. Dorsal, pectoral The regression parameters (a and b), with their 95% and caudal fins mottled with small spots where darkest confidence intervals for LWRs, coefficients of spots are found along the spine of second dorsal fin. Pelvic determination (r2) of G. giuris, are given in Table 2. All fins united but attached to the body only from their LWRs were highly significant (p < 0.0001) with r2 anterior part.